An InBr3 catalyzed one-pot three-component synthesis of functionalized spirodihydrofuran oxindoles via intramolecular alkyne carbonyl metathesis

A new and convenient one-pot methodology for the reaction of N-methyl isatin, alkynes and phenacyl bromides to selectively afford spiro dihydrofuran oxindole derivatives catalyzed by indium bromide under ambient temperature conditions has been documented. The method has been applied for the synthesis of a range of compounds with variable functionalities in good to excellent yields (76-92%). The significant advantages of this protocol are highlighted by excellent yields, cleaner reaction profiles and avoidance of expensive catalysts.